The present invention relates to a cutting insert for a bar peeling operation performed in bars formed of stainless steel or other heat resistant materials wherein the insert has a polygonal form including an upper chip face, an opposite bottom face and a clearance face located therebetween, whereby the intersection of the chip face and the clearance face forms a cutting edge.
Bar peeling as a metal working operation means that a bar is axially displaced through a rotary cutter head, the cutter head provided with several tools arranged in circumferentially spaced apart relationship around the bar. The tools remove from the bar a thin layer of millscale, surface cracks, etc., that results from the hot rolling of such bars or tubes. In order to achieve the best results regarding tolerances and surface finish, two different types of inserts are usually combined in the same holder. German Document No. 35 40 665 discloses such tools equipped with a round roughing insert and a finishing insert usually having straight edges.
European Document No. 0 131 784 discloses a bar peeling tool with an insert having angularly broken (non-linear) edges. Such inserts, however, have somewhat limited utility because they do not enable desired results to be achieved in terms of tolerances and surface finish.
In view thereof, it is a purpose of this invention to provide a new type of insert and a tool which will satisfy close tolerance demands and enable very good surface finish to be achieved, while the insert will enable thick and thin chips to be separated from each other in a better way to achieve a shorter chip length when large feeds are involved, whilst reducing the risk of chip entanglement.
It is another purpose of the invention to provide an insert with an extended lifetime.
It is another purpose of the invention to provide an insert that becomes more economic due to the usage of only one type of insert.
It is yet another purpose of the invention to provide an insert which can more efficiently reduce and counter the tendency for vibrations to occur during a metal cutting operation.